Small Transmission Delay Research Articles

Hybrid-radius spatial network model and its robustness analysis

In many real-world complex networks, their nodes are constrained by spatial positions, which we call spatial networks. Transmission delay and energy consumption are two key performance indicators to make the spatial network work normally, and they exist certain contradictions, i.e., reducing the transmission delay will increase energy consumption, and vice versa. In this paper, a new spatial network model named hybrid-radius spatial network is proposed to balance these two indicators. In this model, the connectivity radii of nodes have two types – the small radius and large radius. First, we study two performance indicators of the hybrid-radius spatial network to make sure that the generated network has a relatively smaller transmission delay and lower energy consumption. Then, we study cascading failures in the hybrid-radius spatial network and compare it with the small-radius spatial network and the large-radius spatial network. On this basis, we further analyze the relationship between the topological characteristics and robustness of this model. Our results show that this model has a heterogeneous betweenness distribution, which leads to its “robust yet fragile” property. In general, the robustness of the hybrid-radius spatial network is between the small-radius spatial network and the large-radius spatial network. The hybrid-radius spatial network model proposed in this paper can provide a simple but effective tool for the study of spatial networks, and the research on the robustness of it can also provide reference for the planning of real-world spatial networks.

Pinning impulsive synchronization of two-layer heterogeneous delayed networks

This article mainly investigates pinning impulsive synchronization of the two-layer delayed network with unidirectional interlayer coupling and transmission delays. The intralayer topologies of different layers are independent each other, and the nodal dynamics in each layer are different as well. Using the Lyapunov stability theory and the auxiliary system method, several pinning impulsive strategies for guaranteeing interlayer generalized synchronization of two-layer delayed networks are put forward. When the impulse interval is fixed as a constant value, the smallest number of pinned nodes and largest impulse interval needed theoretically for ensuring interlayer generalized synchronization are obtained. Specially, when the impulse strengths, the impulse interval, and the number of pinned nodes are respectively set to constant values independent of the impulsive instant, the influences of these parameters on the synchronized region are further discussed. Furthermore, it is found that the relatively small interlayer transmission delay is beneficial to interlayer generalized synchronization. Numerical simulations are presented to verify the effectiveness and correctness of the proposed schemes.

Interlayer synchronization of duplex time-delay network with delayed pinning impulses

This paper mainly focuses on interlayer synchronization in a duplex network setting with the intralayer coupling delay and the interlayer transmission delay via pinning impulsive control. Firstly, based on Lyapunov stability theory, a general pinning impulsive strategy guaranteeing interlayer synchronization is obtained. Then, the minimum number of pinned nodes and the maximum impulse interval needed theoretically for interlayer synchronization are obtained. Moreover, when some parameters, including the impulse strengths, the ratio of pinned nodes and the impulse interval, are fixed certain values, their influences on the stable region are further discussed. It is found that the stable region becomes smaller as the ratio of pinned nodes decreases, and gets larger as the impulse strength with no delay is closer to −1 and that with delay is closer to 0. At the same time, the small intralayer coupling delay and interlayer transmission delay can enlarge the stable region. Finally, numerical simulations are provided to verify the effectiveness and correctness of our results.

Data Fast Transmission Method in Wireless Vehicle Ad-hoc Network

In vehicular ad hoc networks, the current method does not consider the delay of data transmission, resulting in slower vehicle data transmission speed. A vehicle data transmission method based on backbone network is proposed in this paper. Firstly, the characteristics of vehicle ad hoc network are analyzed. Based on the statistics of the road, the vehicle cluster is composed of the vehicles parking on the roadside and no roadside according to the different directions of the vehicle driving. The backbone network is constructed on the basis of the cluster of vehicles, and the data transmission between the vehicles is implemented by the data transmission method of overlay network. This method can overcome the disadvantages of traditional data transmission methods, improve the efficiency of on-board data transmission, and complete the research on fast data transmission method in wireless vehicle ad hoc network. The experimental results show that the proposed method can achieve higher data transmission success rate with lower data transmission overhead and smaller transmission delay.

Design of data transmission system of human-autonomous devices for UAV inspection of transmission line status

The use of unmanned helicopters for line inspection is an important development direction for transmission line inspections. The unmanned helicopter inspection system can partially replace the line inspection workers and the manned helicopter inspection system, timely discover the faults and hidden dangers of the line, and transmit the situation on the ground to the ground control center to make correct judgments and eliminate line faults in time. The composition of the data link of the unmanned aerial vehicle (UAV) is designed as a data-code-coded code link implementation scheme based on single-chip microcomputer, which can realize the uplink remote control information, task information and management information. For multi-rotor UAVs, the load is limited, and long-distance operations are often required. In combination with people’s requirements for image quality, this paper designs a set of high-definition digital image data transmission system with small volume and low transmission delay, capturing images in real time with a high-definition camera mounted on a drone or single-player device, first convert the image to a video signal, and then transmitting the video signal to the modulation end of the microwave transmitter through compression processing, and loading the signal onto the carrier through the microwave transmitter. After being microwaved, the directional radiation is radiated to the microwave receiver of the tension tower or the drone, and the video image signal is demodulated by the microwave receiver. Sending this signal to a hard disk recorder or monitor enables unattended monitoring of the power line all day.

Efficient Routing Protocol Based on Reinforcement Learning for Magnetic Induction Underwater Sensor Networks

In recent research on 3D underwater wireless sensor network (UWSN), magnetic induction communication is a promising candidate, thanks to several unique features, such as small transmission delay, constant channel behavior, and adequate long communication range. However, designing a routing protocol that prolongs the network lifetime and reduces the transmission delay has been still a challenge for a 3D UWSN. In this paper, we propose an efficient routing protocol based on reinforcement learning, in particular, the Q-learning that aims to investigate the resource management in the hierarchical networks. Through defining the single hopping bonus metrics of distance and energy, we deduce the updating formula of the routing algorithm and derive the relationship between energy priority and distance priority. In addition, we set up a regulatory factor to adjust the proportion between energy saving and low delay, and thus, it can meet different needs. The simulation results show that the proposed routing approach outperforms the conventional protocol in extending the network lifetime and reducing the transmission delay.

Analysis and Design of a Wide-Range Soft-Switching High-Efficiency High-Frequency-Link Inverter With Dual-Phase-Shift Modulation

A wide-range soft-switching high-efficiency cycloconverter-type high-frequency-link inverter with dual-phase-shift modulation strategy is proposed in this paper. By adding an auxiliary inductor in primary-side full bridge circuit and adopting center-tapped four-winding transformer structure, the soft-switching range for primary-side switches has been extended. The secondary-side active clamper network is designed to recycle leakage inductor energy, and suppress voltage spikes caused by the resonance of the leakage inductor and the parasitic capacitance of switches. One feature of the proposed inverter is that both the primary-side full-bridge and active clamper network employ phase-shift modulation technique where all switches are driven with nearly 50% duty cycle square signals, hence a simple and reliable transformer-isolated gate drive circuit with small transmission delay is presented. Moreover, all switches in the proposed inverter achieve zero voltage switching, which contributes to higher conversion efficiency as well as higher switching frequency. Analysis, design, and implementation of the proposed inverter are discussed in detail. A 200-kHz laboratory prototype for the high-voltage audio amplifier application is developed and the experimental results are presented to validate the analysis and performance of the proposed inverter.

Data Collection Strategy for Magnetic Induction Based Monitoring in Underwater Sensor Networks

Underwater wireless sensor networks (UWSNs) based on magnetic induction (MI) have been recently proposed as a promising candidate for underwater networking due to its benefits, such as small transmission delay, low vulnerability to environment changes, multipath fading negligibility, and high bandwidth. Most of the UWSN applications are location dependent and, thus, localization plays an important functionality for obtaining sensor positions. In this paper, we first study an MI-based monitoring network in shallow sea, then focus on how to design an optimal node deployment strategy and a clustering algorithm to prolong network lifetime for a 3D-UWSN by reducing the network energy consumption. Using the Voronoi diagram, we propose a high-energy node priority clustering algorithm, in which a cluster head would be selected according to the remaining energy of sensor nodes and the geometry distance among them. Moreover, in order to improve the efficiency of data collection, we use the ant colony optimization to find the shortest path for autonomous underwater vehicle. The simulation results show that the proposed approach outperforms other conventional protocols in some certain scenarios.

Hybrid Communication Topology and Protocol for Distributed-Controlled Cascaded H-Bridge Multilevel STATCOM

Distributed control scheme is preferred to the multiple-modules-based system because of the simple structure, low maintenance, and high scalability. This paper proposes a hybrid communication topology and a route-switching communication protocol to implement the distributed control applied in the cascaded H-bridge (CHB) multilevel static synchronous compensator (STATCOM). The hybrid topology consists of multiple paralleled synchronous communication branches and each branch has very small transmission delay, which makes it possible to apply the low-speed communication network, such as 5 Mb/s optical fiber, to reduce the cost and improve the reliability. The route-switching communication protocol promises the global fault response of the STATCOM as quick as 10 μs by switching from the long normal data to the short fault signal when the module fault occurs. Experiments based on the CHB 13-level STATCOM prototype verify the effectiveness, flexibility, and reliability of the proposed topology and protocol.

Video streaming technologies using ActiveX and LabVIEW

The goal of this paper is to present the possibilities of remote image processing through data exchange between two programming technologies: LabVIEW and ActiveX. ActiveX refers to the process of controlling one program from another via ActiveX component; where one program acts as the client and the other as the server. LabVIEW can be either client or server. Both programs (client and server) exist independent of each other but are able to share information. The client communicates with the ActiveX objects that the server opens to allow the sharing of information [7]. In the case of video streaming [1] [2], most ActiveX controls can only display the data, being incapable of transforming it into a data type that LabVIEW can process. This becomes problematic when the system is used for remote image processing. The LabVIEW environment itself provides little if any possibilities for video streaming, and the methods it does offer are usually not high performance, but it possesses high performance toolkits and modules specialized in image processing, making it ideal for processing the captured data. Therefore, we chose to use existing software, specialized in video streaming along with LabVIEW and to capture the data provided by them, for further use, within LabVIEW. The software we studied (the ActiveX controls of a series of media players that utilize streaming technology) provide high quality data and a very small transmission delay, ensuring the reliability of the results of the image processing.

Energy Efficient and Reliable ARQ Scheme (E $$^2$$ 2 R-ACK) for Mission Critical M2M/IoT Services

Wireless sensor networks (WSNs) are the main infrastructure for machine to machine (M2M) and Internet of thing (IoT). Since various sophisticated M2M/IoT services have their own quality-of-service (QoS) requirements, reliable data transmission in WSNs is becoming more important. However, WSNs have strict constraints on resources due to the crowded wireless frequency, which results in high collision probability. Therefore a more efficient data delivering scheme that minimizes both the transmission delay and energy consumption is required. This paper proposes energy efficient and reliable data transmission ARQ scheme, called energy efficient and reliable ACK (E $$^2$$ R-ACK), to minimize transmission delay and energy consumption at the same time. The proposed scheme has three aspects of advantages compared to the legacy ARQ schemes such as ACK, NACK and implicit-ACK (I-ACK). It consumes smaller energy than ACK, has smaller transmission delay than NACK, and prevents the duplicated retransmission problem of I-ACK. In addition, resource considered reliability (RCR) is suggested to quantify the improvement of the proposed scheme, and mathematical analysis of the transmission delay and energy consumption are also presented. The simulation results show that the E $$^2$$ R-ACK scheme achieves high RCR by significantly reducing transmission delay and energy consumption.

Mobility Tolerant Firework Routing for Improving Reachability in MANETs

In this paper, we investigate our mobility-assisted and adaptive broadcast routing mechanism, called Mobility Tolerant Firework Routing (MTFR), which utilizes the concept of potentials for routing and improves node reachability, especially in situations with high mobility, by including a broadcast mechanism. We perform detailed evaluations by simulations in a mobile environment and demonstrate the advantages of MTFR over conventional potential-based routing. In particular, we show that MTFR produces better reachability in many aspects at the expense of a small additional transmission delay and intermediate traffic overhead, making MTFR a promising routing protocol and feasible for future mobile Internet infrastructures.

Design of High Speed Data Acquisition System Based on FPGA

with the rapid development of information technology, a variety of data acquisition and processing in the modern industrial control and scientific research have become an indispensable part. The data acquisition system is a bridge between the smart instruments and the outside physical world, and it is also an important way to get information. The implementation of high-speed data acquisition and real-time transmission has always been an important research direction in data acquisition system. The development of FPGA technology has provided new solution. In this paper, the typical architecture of data acquisition system was given. The hardware part mainly consists of front high-speed A/D converter module, master controller of FPGA, and USB interface circuit has been realized. According to the idea of design and the procedure of program, software part has been completed. The results show that the system has the characteristics of fast acquisition speed, high storage capacity, small transmission delay, high stability and so on.

An (m,k)-Firm Real-Time Aware Fault-Tolerant Mechanism in Wireless Sensor Networks

Many real-time routing mechanisms have been proposed to support the newly developed wireless sensor networks (WSNs) applications such as the transmission and retrieval of multimedia traffic. However, the inherent source constraints of sensor network and instability of wireless communication set quite a problem for the existing routing mechanisms to meet the quality of service (QoS) requirements of some specific QoS-aware applications. Hence, real-time fault-tolerant schemes are highly desired for WSNs to address these challenges. In this paper, we propose an -firm-based real-time fault-tolerant mechanism, which helps routing mechanisms to achieve specific QoS requirement by employing a local status indicator (LSI) at each sensor node to monitor and evaluate the local conditions of node and network. Therefore, specific fault recovery mechanisms could be implemented for ensuring an acceptable QoS performance, according to the evaluated LSI values. By using this fault-tolerant scheme, each node dynamically adjusts its transmission capability to mitigate the performance degradation of real-time service caused by network faults and to maintain the desired reliability and timeliness. Simulation result shows that LSI cannot only help to reduce the effects of congestion, link failure, and void, but also reach higher successful transmission ratio and smaller transmission delay.

Joint Forensics-Scheduling Strategy for Delay-Sensitive Multimedia Applications over Heterogeneous Networks

High quality multimedia forensics service is increasingly critical for delay-sensitive applications over heterogeneous networks. Up to now, it is a challenging problem, where the demand for less forensics overhead, higher authentication level and smaller transmission delay needs to be reconciled with the limited and often dynamic network resources. Traditional multimedia forensics mechanisms, however, either overlook the available network resource or neglect the interaction between multimedia forensics and network scheduling. This work presents a novel framework for delay-sensitive multimedia applications over resource-limited heterogeneous networks by jointly considering multimedia forensics, network adaptation, and deadline-driven scheduling. In particular, we develop a joint forensics-scheduling scheme, which allocates the available network resources based on the affordable forensics overhead and expected quality of service, adaptively adjusts the scalable media-aware forensics, and schedules the transmissions to meet the application's delay constraints. Through analysis and simulation, we demonstrate that the proposed scheme not only can provide a satisfying multimedia forensics service with nearly full utilization of the network resource, but also can achieve substantial performance improvements compared to other reference approaches.

Delay Performance Analysis for Supporting Real-Time Traffic in a Cognitive Radio Sensor Network

Traditional wireless sensor networks (WSNs) working in the license-free spectrum suffer from uncontrolled interference as the license-free spectrum becomes increasingly crowded. Designing a WSN based on cognitive radio can be promising in the near future in order to provide data transmissions with quality of service requirements. In this paper we introduce a cognitive radio sensor network (CRSN) and analyze its performance for supporting real-time traffic. The network opportunistically accesses vacant channels in the licensed spectrum. When the current channel becomes unavailable, the devices can switch to another available channel. Two types of channel switchings are considered, in periodic switching (PS) the devices can switch to a new channel only at the beginning of each channel switching (CS) interval, while in triggered switching (TS) the devices can switch to a new channel as soon as the current channel is lost. We consider two types of real-time traffic, i) a burst of packets are generated periodically and the number of packets in each burst is random, and ii) packet arrivals follow a Poisson process. We derive the average packet transmission delay for each type of the traffic and channel switching mechanisms. Our results indicate that real-time traffic can be effectively supported in the CRSN with small average packet transmission delay. For the network using PS, packets with the Poisson arrivals experience longer average delay than the bursty arrivals; while for the network using TS, packets with the bursty arrivals experience longer average delay.

Dynamical Jumping Real-Time Fault-Tolerant Routing Protocol for Wireless Sensor Networks

In time-critical wireless sensor network (WSN) applications, a high degree of reliability is commonly required. A dynamical jumping real-time fault-tolerant routing protocol (DMRF) is proposed in this paper. Each node utilizes the remaining transmission time of the data packets and the state of the forwarding candidate node set to dynamically choose the next hop. Once node failure, network congestion or void region occurs, the transmission mode will switch to jumping transmission mode, which can reduce the transmission time delay, guaranteeing the data packets to be sent to the destination node within the specified time limit. By using feedback mechanism, each node dynamically adjusts the jumping probabilities to increase the ratio of successful transmission. Simulation results show that DMRF can not only efficiently reduce the effects of failure nodes, congestion and void region, but also yield higher ratio of successful transmission, smaller transmission delay and reduced number of control packets.

A distributed MAC scheme supporting voice services in mobile ad hoc networks

AbstractFuture mobile ad hoc networks are expected to support voice traffic. The requirement for small delay and jitter of voice traffic poses a significant challenge for medium access control (MAC) in such networks. User mobility presents unique difficulties in this context due to the associated dynamic path attenuation. In this paper, a MAC scheme for mobile ad hoc networks supporting voice traffic is proposed. With the aid of a low‐power probe prior to DATA transmissions, resource reservation is achieved in a distributed manner, thus leading to small packet transmission delay and jitter. The proposed scheme can automatically adapt to dynamic path attenuation in a mobile environment. Statistical multiplexing of on/off voice traffic can also be achieved by partial resource reservation for off voice flows. Simulation results demonstrate the effectiveness of the proposed scheme. Copyright © 2009 John Wiley & Sons, Ltd.

Effect of Small Transmission Delay on Human Behavior in Audio Communication

Transmission delay in audio communications is a well-known obstacle to achieving smooth communication. However, it is not known what kinds of effects are caused by small delays. We hypothesized that the small delay in the listener's responses disturbs the speaker's “verbal conditioning, ” where the verbal behavior of the speaker varies in accordance with the listener's responses. We examined whether the small delays in the listener's responses disturb the speaker's verbal conditioning using an artificial-grammar learning task. The results suggested that a 300-ms delay disturbed the participants' verbal conditioning although they were not adequately aware of the delay.

Triple loop networks with small transmission delay

The problem of finding multiloop networks with a fixed number of vertices and small diameter has been widely studied. In this work, we study the triple loop case of the problem by using a geometrical approach which has been already used in the double loop case. Given a fixed number of vertices N, the general problem is to find ‘steps’ s 1, s 2, …, s d ∈ Z N , such that the diagraph G( N; s 1, s 2, …, s d ), with set of vertices V = Z N and adjacencies given by v → v + s i ( mod N), i = 1, 2, …, d, has minimum diameter D( N). A related problem is to maximize the number of vertices N( d, D) when the degree d and the diameter D are given. In the double loop case ( d = 2) it is known that N(2, D) = ⌈ 1 3 (D+2) 2⌉ − 1 . Here, a method based on lattice theory and integral circulant matrices is developed to deal with the triple loop case ( d = 3). This method is then applied for constructing three infinite families of triple loop networks with large order for the values of the diameter D ≡ 2, 4, 5( mod 6), showing that N(3, D) ⩾ 2 27 D 3 + O(D 2) . Similar results are also obtained in the more general framework of (triple) commutative-step digraphs.